Those were copyright claims, true, but that doesn't change the fact that companies still sought to protect what they felt were their innovations. There were many other cases involving many other companies, such as Sega vs Accolade. The only thing that has changed is companies have realized patents are a better means to that end because copyright does not, in their eyes, afford sufficient protection.

>Lotus 123 would never have been able to exist if software patents had been there at the time.

It's impossible to say that without considering what patents they'd have been able to secure in the first place, and even then it's almost certain they'd have existed. Software patents exist today and there is no shortage of clones in the market, even for products that had been heavily patented.